Abstract
Monitoring orobservation with use of sensors which is distributed over a large constructionsite needs cables of great length and takes a lot of labor and trouble. Thispaper reports a wireless sensor system for monitoring ground displacement whichhas been newly developed by combining GPS receiver and wireless sensortechnology. The wireless sensor is so designed that has a radio communicationdistance of several hundreds meters, is battery-operated for over a month, andcan observe ground displacement with about the same precision as existing wiredmonitoring system using GPS. Performance test on the prototype sensor systemhas been conducted in a dam construction site, and expected performance hasbeen verified.
